My 64 GB iPad is full to the brim - it doesn't take long. My music collection alone is about 30 GB. I will likely buy the 128 GB version of the iPad in due time, as this old iPad 2 is in need of a refresh anyways.
That being said, the reactionary press about the Surface Pro is a bit silly. You *can* ditch the recovery partition to free up a lot of space, but that doesn't change the fact it is running full (non RT) Windows 8, which takes up a lot of space. The 64 GB versions of the Surface Pro shouldn't even exist, IMO. Even the 128 GB versions would be far too small for me for a tablet running a full fledged OS.
But hey, at least with these Surface Pro devices, you have expansion options. They have USB ports and memory card slots that will take cheap storage options, whether it be a 64 GB SD card, a 256 GB USB Flash drive, or something like a plain old USB external hard disk.
You don't have that option at all with the Apple products. A lot of people have bought 16 GB iPad models, only to find out that a few major game titles can fill that up quite rapidly, leaving you with no expansion options.
For example, one of my favorite iPad timesinks is Need for Speed: Most Wanted - which takes up near 2 GB of space on the iPad.